SPSFAM ERP

Table 3. Recovery of kestose in the Fructan Assay Kit (K-FRUC) procedure performed with and without the sucrase/amylase incubation step. Recovered kestose (mg/assay) Kestose (mg/assay) Without incubation with sucrase mixture With incubation with sucrase mixture (according to K-FRUC)

Recovery % w/w

2 5

2.1 5.0

2.1 4.9

100.0 98.4 100.0 100.8 96.2

10 20 50

10.1 19.5 50.7

10.1 19.7 48.2

Sucrose - Under the incubation conditions employed, sucrose is essentially completely hydrolyzed and removed and there is negligible hydrolysis of kestose. In order to determine the effect of matrix on recovery of fructan, a variety of food and feed samples were spiked with inulin (and in one case, levan) (Tables 4 and 5). A range of animal food and feed samples were spiked with three levels of inulin and analyzed to obtain recovery values. GoCat dry cat food and timothy grass were spiked with known quantities of either inulin or levan and recoveries were determined by analyzing and comparing fructan values for the sample, with and without the added spike. Timothy grass samples with two levels of spike of both inulin and levan and GoCat dry cat food with a single level of spike with either inulin or levan were analyzed in duplicate by one analyst on a single occasion. The data in Tables 4 and 5 shows that obtained recoveries were within the range required by AOAC for this method. 8.8 0.16

20